Isolated matrix current source rectifier in discontinuous conduction mode

Abstract

The current source rectifier is a buck type rectifier, and it has advantages such as output voltage variation in wide range, high power density, unity power factor and suitable for variable frequency applications. However, most of them operate in continuous conduction mode where the output current is assumed to be a DC value. When the output inductor is small and/or the converter is operating in light load, the dc link current will become discontinuous, and input current will be distorted. In this paper, a three-phase isolated matrix current source rectifier (CSR) is designed to work in discontinuous conduction mode (DCM), where high frequency transformer is used to provide galvanic isolation. A novel symmetric space vector modulation (SVM) scheme is proposed to conduct bidirectional current. Two loop control based on feedback linearization in dq frame is applied to control input power factor and output voltage. Power factor correction (PFC) and low total harmonic distortion (THD) is verified by simulation. It has advantage in high power density and step down voltage application.